Add Docker deployment configuration

- Add Dockerfile for production (multi-stage build)
- Add Dockerfile.dev for development with hot reload
- Add docker-compose.yml with 5 services (web, mariadb, redis, celery-worker, celery-beat)
- Add docker-compose.dev.yml for development overrides
- Add .dockerignore for optimized builds
- Add docker/entrypoint.sh startup script
- Add .env.docker.example template
- Add Makefile for common commands
- Add deploy.sh for one-command deployment
- Update config/settings/selfhosted.py to support MariaDB via DATABASE_URL
- Add mysqlclient to requirements.txt for MariaDB support
- Update .gitignore to exclude .env.docker

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,65 @@
+# ===================================================================
+# Stage 1: Builder - Install dependencies
+# ===================================================================
+FROM python:3.12-slim-bookworm AS builder
+
+# Install build dependencies for mysqlclient and other packages
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    gcc \
+    default-libmysqlclient-dev \
+    pkg-config \
+    && rm -rf /var/lib/apt/lists/*
+
+# Install Python dependencies
+COPY requirements.txt /tmp/
+RUN pip install --user --no-cache-dir -r /tmp/requirements.txt \
+    && pip install --user --no-cache-dir mysqlclient gunicorn
+
+# ===================================================================
+# Stage 2: Runtime - Minimal production image
+# ===================================================================
+FROM python:3.12-slim-bookworm
+
+# Install runtime dependencies only
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    default-mysql-client \
+    curl \
+    && rm -rf /var/lib/apt/lists/*
+
+# Create django user (non-root for security)
+RUN useradd -m -u 1000 -s /bin/bash django
+
+# Set working directory
+WORKDIR /app
+
+# Copy Python dependencies from builder stage
+COPY --from=builder /root/.local /home/django/.local
+
+# Copy application code
+COPY --chown=django:django . /app/
+
+# Create directories for media and static files
+RUN mkdir -p /app/media /app/staticfiles && \
+    chown -R django:django /app/media /app/staticfiles
+
+# Switch to django user
+USER django
+
+# Add .local/bin to PATH for installed packages
+ENV PATH=/home/django/.local/bin:$PATH
+
+# Set Python to run in unbuffered mode (better for Docker logs)
+ENV PYTHONUNBUFFERED=1
+
+# Expose port 8000 for Gunicorn
+EXPOSE 8000
+
+# Health check - ping the API endpoint
+HEALTHCHECK --interval=30s --timeout=10s --start-period=40s --retries=3 \
+    CMD curl -f http://localhost:8000/api/ || exit 1
+
+# Entrypoint script handles migrations, static collection, and service startup
+ENTRYPOINT ["/app/docker/entrypoint.sh"]
+
+# Default command is to run Gunicorn
+CMD ["gunicorn"]